From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965006Ab3DSWDR (ORCPT ); Fri, 19 Apr 2013 18:03:17 -0400 Received: from terminus.zytor.com ([198.137.202.10]:55562 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964936Ab3DSWDQ (ORCPT ); Fri, 19 Apr 2013 18:03:16 -0400 Message-ID: <5171BF0A.8010402@zytor.com> Date: Fri, 19 Apr 2013 15:02:50 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: "Bryan O'Donoghue" CC: Borislav Petkov , linux-kernel@vger.kernel.org, x86@kernel.org, fenghua.yu@intel.com Subject: Re: [PATCH] x86: Add check for P5 to microcode_intel_early References: <1366392183-4149-1-git-send-email-bryan.odonoghue.lkml@nexus-software.ie> <20130419191128.GA21991@pd.tnic> <5171AA86.604@nexus-software.ie> <20130419205515.GA3075@pd.tnic> <20130419212514.GC3075@pd.tnic> <5171BAD6.4040003@nexus-software.ie> In-Reply-To: <5171BAD6.4040003@nexus-software.ie> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/19/2013 02:44 PM, Bryan O'Donoghue wrote: > On 19/04/13 22:25, Borislav Petkov wrote: >> On Fri, Apr 19, 2013 at 10:55:15PM +0200, Borislav Petkov wrote: >>> Just filter out P5 and earlier. The code already does that for CPUs >>> which don't have CPUID. >> >> Actually, an alternative - more practical albeit not very accurate > > More practical ? Hmm - the MSRs don't exist for < P5 Yes, and that is definitional. I like doing this check before boring down in the code too far, however, I want to make it so that it is structurally clear that this is for Intel; other CPU vendors might theoretically have other criteria. Architecturally, I would prefer to do this check early in load_ucode_intel_{bsp,ap}() but I would be okay with putting it in load_ucode_bsp()/local_ucode_ap() as well as long as the test is conditional on the Intel vendor check. More importantly, though: I really would like to get a fix *today*. -hpa